Means adapting electric flash lights for testing electric circuits



May s', 1928. 1,668,847

L. T. HOOK MEANS ADAPTING ELECTRIC FLASH LIGHTS FOR TESTING ELECTRIC CIRCUITS Filed Jan. 1927 \NVENTOR ATTORNEY Patented May s, 1928.

. UNITED STATES PATENT OFFICES."

LEONARD T. HOOK, OF SEATTLE, WASHINGTON.

MEANS annr'rme nnno'rarc FLASH ilmxrrs non 'rns'rrivo nnnc'rnro crno'orrs.

, Application filed lianuary 29,1927. Serial No 165 ,5533.

In determining whether or notQan electric circuit is intact, a common practice among electricians has been to test thesame by a bell and battery, thus necessitating the car rying of instruments which possessed no particular utility in an electricians work, except for this single purpose. An electric flashlight, however, is a necessary part of the equipment required in such work, and my invention has reference to instrumentalities whereby such a flashlight, in addition to performing its usual functions, may also be utilized in lamping out an electric circuit.

The objects of m invention, generally stated, are, to provi e, in an electric flashlight of ordinary construction, a sli htly modified form of base,-and a devicea apted to be detachably mounted thereto,having a pair of electrical contact points attachable, for instance, to "the respective wires of an electridcircuit, and whereby a flash of light will indicate if said circuit is unbroken; and, to afford, such a device which is light in weight, less cumbersome than the other means commonly employed for making such tests, and inexpensive to produce.

In the accompanying drawings- Figure l'is a front elevation of the device I complete, the connecting wires for a pair of electrical contact clips being shown in broken sections; and,

Fig. 2, a-vertical sectional viewof the casi which in its general form presents the usual construction, a sleeve 4 is fixedly secured centrally thereof and extends therein, as indicated in Fig. 2, for approximately half the height of the base. A collar 5 is mounted on and slidably engages said sleeve. lar is provided in its upper portion withan axially aligned opening reduced in diameter.-

and interiorly threaded, as at 6, and is put under tension by a strong helical spring 7,

Said col secured to said portion and the lower inner section of the base.

Another member, generally designated as 8, carries an axially aligned upstanding section, the lower portion of which, denoted as 9, is circular in cross section and slidably mounted within the sleeve 4, and its upper portion 10, exteriorly threaded, engages the threaded portion 6 of said collar. A circular outlined and knurled portion 11, havin I integral therewith an exteriorly threade section 12 reduced in diameter, provides a' base for the member 8, and a cover for a casing 13, which is threadedly engaged with the section 12. Said casing, cylindrical in form, is designed to be made of hard rub her or any other suitable insulating material.

A'spindle 14, made of material conductive of electricity, having at one end a head 15 and at the other end an exteriorly'threaded section 16, is fixedly secured within the member 8, and completely insulated thereiron; the insulation therefor being denoted as 1 20 designates an electric contactv member disposed on but insulated from the spindle, and contacting with the member 8, and 21 an electrical contact member threadedly secured to said spindle, and insulated from the member 8, the said members providing respectively positive and negative pole. connections for the device withthe flashlight, as will be presently described. An insulated wire, denoted as 22, is secured to each of said contact members by a screw 23', and extends out of the lower end of the casing througha central opening 24 therein, and each is adapted to establish electrical commnnication from 'thejcontact member with which it is thus connected to and through a metallic,clip 25, secured to its outer terminal. 26 denotes a rubber 'protecting tube disposed on each of said wires, and adjacent its'clip.

When this modified form 'ofthe base is connected with the flashlight, the spring 7 serves to force the collar 5. against the bot-- tom of the battery 2 andthus permit a normal flow of the electric current through the flashlight and thereby let it function as primarily intended, the collar obviously taking the place of the .free terminal of a like 7 s rin" flashlight.

g disposed in the base' .of an ordinary,

In utilizing the devieqlg part8 eonn with the casing l3 are assembled as hereto vfore described, the said upstanding section of the member 8 is inserted in the sleeve 4 and the threaded portion 10 of said member e is brought into engagement with the threaded opening 6 of the collar.

V cated in Fig. 2, thus. when the electriccurrent is turned on in the flashlight, diverting it from its normal flow through the flashlight into and through the present device.

The electrical contact member derives its electro-motive force through the casing of the flashlight and the elements shown which, as is evident, are adapted to connect it elec- 2 trically therewith, thereby affording a positive pole connection for the device, and the electrical contact member 21, insulated from said elements and connected with the insulated spindle contacting with the bottom of 5 the battery as described, derives its electromotive force through the spindle, thereby providing a negative pole connection for the device.

The operating button of the flashlight hav ing been depressed and its usual connecting mechanism slid into a position to keep the light on when the circuit therefor is complete, the device is ready for use in testing an electrical, circuit. This is accomplished,

as indicated in Fig. 1, by attaching the clips 25 to the wires to be tested, denoted as 27, and if the wires belong to such a circuit and the same is intact, an electrical circuit will be established through said wires, the device and the flashlight, and the flashlight will be illuminated. As said clips are energize-d electrically, obviously, similar tests may be made by simply. touching the clips to opposing points in any other electrical circuit. A linking together of the clips will cause 'theflashlight to function by the current flowing through it and the device, and when it is equipped with the modified base it is complete as a flashlight. It may be noted, therefore, the device-exclusive of said basebeing small, of lightweight construction, and having no parts which are frail or liable to get out of order, may be conveniently carried separately of the base and quickly attached to the flashlight when a test is to be made, or, if desired, it may be carried at tached to the flashlight, as shown, without interfering with the uses for which the flashlight was originally designed to be employed.

In the present embodiment of the invention, I have shown and described the device as applicable to an electric flashlight having a helical spring disposed in its base, and which serves as a contact with a battery in When the device is screwed into place in the flashlight, the

neeaeu the flashlight. As will be obvious to those skilled in the art, the device may also be employed with electric flashlights having such a contact of a different type, and changes in and modifications of the construction described maybe made without departing from the spirit of my invention or sacriflcing its advantages, hence it is desired that I be not confined to the specific structure set forth.

- I claim:

1. In combination with an electric flashlight having a detachable base, a sleeve secured to the base, a collar slidably mounted thereover having an interiorly threaded section, a'spring adapted to force the collar in contact with the negative pole of a battery in the flashlight, a member having a base portion carrying an upstanding section, a spindle, terminating at one end in a head and at the other end in an exteriorly threaded section, extending through the 'member and insulated therefrom, said u standing sect-ion slidably enga ing t e sleeve and threadedly engaging t e collar and whereby the collar may be withdrawn from said contact with the battery and replaced by the head, an electric contact member, contacting with the first-named memher and insulated from the spindle, adapted to provide a positive pole connection with the flashlight, an insulated casing secured to said base portion, and means secured to said contacts and extending through the casin for establishing an electric circuit 'throug the flashlight and said instrumentalities.

2. In combination with an electric flashlight having a detachable base, a sleeve secured to the base, a collar slidably mounted thereover, having an axially aligned opening reduced in diameter and interiorly threaded, a spring disposed in the base and secured to the collar adapted to force the collar in contact with the negative pole of the adjacent battery in the flashlight, amemoer having a portlon circular in cross section surmounted by an exteriorly threaded portion, a spindle extending throu h the member and insulated therefrom, sai member'slidably engaging edly engaging the collar and whereby the collar may be released from said contact with the battery and displaced by'the head, an electric contact member contacting with the first-named member and adapted to afford a'positive pole connection with the flashlight, and a second electric contact member secured to the spindle adapted to afford a negative pole connection with the flashlight.

3. In combination with an electric flashlight having a detachable base, a sleeve secured to the base, a collar slidably mounted thereover, havin in its top ortion an interiorly threaded section, spring means disthe sleeve and threadi posed in the base and secured to the collar adapted to force the collar in contact with the negative pole of the adjacent battery in the flashlight, a member operable in the sleeve and threadedly engaging the top portion of the collar, and a rod extending through and insulated from the member, said member being adapted to withdraw the collar from said contact and effect a like contact of the rod with the battery, and thereby permit electro-motive force to be diverted from the battery to said rod.

4. In a device of the class described, a base adapted to be attached to an electric flashlight, a sleeve secured centrally of the base, an electrical contact, comprising a collar slidably mounted over the sleeve, said collar having an opening, reduced in diam-' eter, in axial alignment with the sleeve and interiorly threaded, a spring adapted to ber threadedly engaged with the collar for retracting the same.

5. In a device of the class described havin a base adapted to be attached to an electric flashlight, a guide way in said base and a casing interiorly threaded, a connecting member, comprising a circular outlined knurled portion to provide a cover for the casing, an integral exteriorly threaded section, reduced in diameter, at one side of the portion adapted to threadedly engage the casing, an upstanding axially aligned sec-t tion on the other side of the portion, insertable in the guide way, and an insulated electrical contact member disposed in the connecting member and projecting from the base and the outer terminal of said section.

LEONARD T. HOOK. 

